The -ckvar- package is a package of Stata utilities which allow data
validation or scoring rules to be attached to the variables in a
dataset, making the dataset self-contained and self-validating, even
across -merge-s or -append-s. Validation rules can be entered and
edited via a dialog box, so even people who are not Stata-aware can
add simple validation rules. For Stata aficionados, do-files can be
attached to variables, allowing very complicated rules. Validation
rules can be printed out in fashion similar to -codebook-, and the
commands for attaching the validation rules can be dumped into a do-
file for future use.